Hopatcong fishes for weed problem solution

Herald file photo
Sun shines on an aquatic weed that covers most of the water in a Lake Hopatcong cove. Hopatcong Mayor Michael Francis is trying to convince the state Department of Environmental Protection to consider using a breed of sterilized fish to control the biomass in the lake..

HOPATCONG -- Today, Candlewood Lake in Sherman, Conn., is beautiful and pristine. In the summer months, its clear, glassy waters attract weekend boaters, vacationing families and outdoor adventurers from around the New England area.

Seven years ago, however, Candlewood Lake was barely recognizable. Its surface was clogged with mass of slimy, green weeds, the type that may look all too familiar to Lake Hopatcong residents. After years of equally familiar, if not ineffective, remedies -- annual lake drawdowns, weed harvests and chemical treatments -- The Candlewood Lake Association (CLA) decided to try something new.

In June 2015, the CLA began to introduce a breed of sterile grass carp into the lake in hopes that the fish would be able to accomplish what the humans had not and take care of the weed problem once and for all. Now, two years later, it looks as though the experiment has worked.

On Oct. 20, Hopatcong Mayor Michael Francis, along with two members of the Lake Hopatcong Foundation, traveled to Candlewood Lake to see the miracle fish in action.

"This could work for us," Francis said, speaking with the New Jersey Herald after his trip. "These fish are natural little weed killers. They eat the biomass, don't disrupt the eco-system and can't reproduce. It's all very controlled and scientific. This could part of a viable, long-term solution to the Lake Hopatcong weed problem instead of just another quick fix."

Unfortunately, Francis said, the idea of introducing the carp into Lake Hopatcong has one major roadblock standing in its way: in New Jersey, triploid grass carp like those introduced into Candlewood Lake, are considered an invasive species.

According to the New Jersey Division of Fish and Wildlife, grass carp can only be introduced into a bodies of water that measure 10 acres or less in size, and where it can be reasonably expected that the fish can be prevented from escaping.

Unfortunately, Francis said, Lake Hopatcong -- about 2,500 acres -- falls well outside those established state parameters. In addition, as Lake Hopatcong feeds into the Musconetcong River, containment issues would need to be addressed.

"I feel like I'm shouting into the wind at this point," Francis said. "I started doing research on this program about two years ago. I have repeatedly pointed out to the (Department of Environmental Protection) that these carp are sterilized and can be easily contained. They prefer to stay in quiet coves, which are the areas where we see the biggest weed problems. It's frustrating, because I really feel that this could mean a positive change for the lake, but we can't get permission to even give it a try."

Candlewood Lake, which covers more than 5,000 acres, has solved the containment issue by netting off tributaries and other waterways to keep the carp from swimming out of the lake.

Donna Macalle-Holly, acting executive director of the Lake Hopatcong Foundation, said that the fact-finding trip to Connecticut had been "very enlightening."

"Candlewood Lake actually looks a lot like Hopatcong," she said. "It's a very residential lakefront with a lot of boat traffic and smaller coves. They have been dealing with the same invasive plant life -- an aquatic weed called Eurasian Watermilfoil -- that we have. When we went to see Candlewood Lake, they took us out on a boat trip to see some of the areas where the carp had been introduced. It was honestly very impressive. You can still see the weeds a few feet below the surface, but since the carp eat from the top down, the surface of the lake is clean and clear."

According to information found on the CLA's website, grass carp were first introduced into Candlewood Lake in 2015. Another 4,450 were stocked this previous summer.

Mark Howarth, CLA's director of education and outreach, said that while the program is still in its infant stages, the members of the association are very hopeful.

"This is not an overnight solution," Howarth said. "When the fish are introduced, they are only about 12 inches long. It will take us a few years to really be able to evaluate their effectiveness, but I think that when you combine them with other methods of weed control, you will definitely start to see some results."

Last year, Howarth said, Candlewood Lake initiated a 6-foot drawdown in order to help keep the weed problem under control.

So far, he said, there have not been any problems with the fish.

"We actually attached radio trackers to 48 of the carp to help keep track of where they were schooling," he said. "They seem to prefer calm, quiet coves, which is great, because that's where the weeds tend to be. Since milfoil needs sunlight to grow, the shallower areas tend to be the most likely spots to get overrun with the stuff."

Marty Kane, board member for the Lake Hopatcong Foundation, admitted that he was somewhat skeptical about the idea of the carp before the trip.

"The phrase 'invasive species' is obviously going to make people nervous," he said. "I didn't know much about this before we went to Candlewood, but I came back really impressed. One of the first questions I asked was how the local fisheries had responded. Apparently, it took a little while for them to warm up to the idea, but pretty soon they realized that the carp would be a less harmful solution than chemical remedies. In addition, when the milfoil is under control, the native plants in the lake will be able to start to make a comeback, which, ultimately, will mean a healthier lake and healthier fish. I figured that if the fishermen could get on board with this, so could I."

Howarth said that because the carp are stocked for a specific purpose, it is illegal to fish for them.

"We have posted signs around the lake letting people know that the carp have to be released if they are caught," he said. "They wouldn't hurt you if you ate them, but they're there for a purpose. We haven't had any problems, people seem perfectly willing to just toss them back in the water."

The next step, Francis said, is going to be to get the Department of Environmental Protection to engage in a conversation.

Francis said "We came back from the trip armed with a lot of information. We're going to meet with the Lake Hopatcong Commission and start trying to get some other folks on board. After that, I think we'll be heading down to Trenton to talk to the DEP about the possibility of allowing us to introduce a small number of carp into Crescent Cove. I think it's going to be a heavy lift, but at least we're starting to get this information out there. I'm not ready to give up on this idea just yet."

The Lake Hopatcong Commission is a governing body made up of representatives from Roxbury, Hopatcong, Jefferson and Byram, the four municipalities that share the Lake Hopatcong shoreline.

According to the Department of Fish and Wildlife, the carp can grow to between 25 and 40 pounds, and can live for more than 10 years.

Lakes like Candlewood restock the carp every few years or so, Howarth said, to account for natural attrition.

"It's really not too bad, cost-wise," he said. "Since we bought in bulk, we got each fish for $6. It adds up, yes, but after this first couple of years when the fish are still young and getting acclimated, it won't be an annual expense."

Howarth said that so far, the carp have been doing well.

"They really aren't a problem," he said. "They're painfully shy, so they don't bother people at all. They exsist on a vegetarian diet, so they aren't a threat to any of the other fish in the lake, and they certainly seem to be enjoying the weeds. Like I said, it will be a while before we can really start to gauge results, but we're very hopeful about this program."

Katie Moen can also be reached on Twitter: @KMoenNHJ or by phone: 973-383-1230.

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